According to a survey by JEITA (Japan Electronics and Information Technology Industries Association), an average viewing time of the TV per day is 4.5 hours. With changes in life style today, however, it is known that the TV is not always watched for 4.5 hours.
For example, when the TV is viewed while making preparations to go to the company or to school or eating breakfast in the morning, the TV screen is not viewed uninterruptedly and eyes may be shifted or a conversation may be held with others when a program such a weather forecast that is sufficiently understood only with audio input is broadcast. Then, an interesting keyword broadcast in current affairs news or sports news may cause the viewing of the TV screen to start again, which is frequently observed behavior.
That is, so-called “viewing while doing something else” in which the TV is just turned on as a substitute for a clock in the morning and more recently, the sound of the TV is just heard while operating a PC (personal computer) in the evening is increasing as typical view forms of the TV. If such “viewing while doing something else” is done, power is uselessly consumed while the TV screen is turned on. Thus, a display apparatus that analyzes a user's viewing state by providing an image sensor in a periphery of the TV screen and detecting a lace by the image sensor and exercises power saving control optimal to the viewing state.